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TitleClimate and permafrost effects on the chemistry and ecosystems of High Arctic Lakes
AuthorRoberts, K E; Lamoureux, S F; Kyser, T K; Muir, D G C; Lafrenière, M J; Iqaluk, D; Pienkowski, A J; Normandeau, AORCID logo
SourceScientific Reports vol. 7, no. 13292, 2017, 8 pages, Open Access logo Open Access
Alt SeriesNatural Resources Canada, Contribution Series 20170107
PublisherSpringer Nature
Mediapaper; on-line; digital
File formatpdf
ProvinceNunavut; Northwest Territories
NTS78F/15; 89B/04
AreaMould Bay; Melville Island; Cape Bounty; Headwater Lake; Prince Patrick Island
Lat/Long WENS-120.0000 -119.0000 76.2500 76.0000
Lat/Long WENS-110.0000 -109.0000 74.0000 73.7500
Subjectslake water geochemistry; permafrost; precipitation; climate, arctic; limnology; diatoms; Arctic char (Salvelinus alpinus)
Illustrationslocation maps; graphs; plots; histograms
Released2017 10 16
AbstractPermafrost exerts an important control over hydrological processes in Arctic landscapes and lakes. Recent warming and summer precipitation has the potential to alter water availability and quality in this environment through thermal perturbation of near surface permafrost and increased mobility of previously frozen solutes to Arctic freshwaters. We present a unique thirteen-year record (2003 - 16) of the physiochemical properties of two High Arctic lakes and show that the concentration of major ions, especially SO42-, has rapidly increased up to 500% since 2008. This hydrochemical change has occurred synchronously in both lakes and ionic ratio changes in the lakes indicate that the source for the SO42- is compositionally similar to terrestrial sources arising from permafrost thaw. Record summer temperatures during this period (2003 - 16) following over 100 years of warming and summer precipitation in this polar desert environment provide likely mechanisms for this rapid chemical change. An abrupt limnological change is also reflected in the otolith chemistry and improved relative condition of resident Arctic char (Salvelinus alpinus) and increased diatom diversity point to a positive ecosystem response during the same period.
Summary(Plain Language Summary, not published)
Arctic warming and permafrost change increases soil water flushing from deep in the seasonal active layer. Increased soil water drainage is sufficient to rapidly alter the chemistry of downstream lakes and at rates much higher than possible by river inflows alone. These chemical changes constitute abrupt impacts to large and deep Arctic lakes previously attributed only to small ponds. Trace element analysis of Arctic charr otoliths (ear bones) indicates that permafrost solute transfer also imparts an abrupt elemental change and suggest the potential for a similar rapid response by the aquatic food web. Diatom and fish indicators suggest rapid permafrost transfers, in conjunction with lake ice cover reductions, result in amelioration of the aquatic environment in less than a decade.

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